This patch contains updated scripts to reduce qemu build time by
[kvmfornfv.git] / kernel / arch / xtensa / kernel / pci-dma.c
1 /*
2  * DMA coherent memory allocation.
3  *
4  * This program is free software; you can redistribute  it and/or modify it
5  * under  the terms of  the GNU General  Public License as published by the
6  * Free Software Foundation;  either version 2 of the  License, or (at your
7  * option) any later version.
8  *
9  * Copyright (C) 2002 - 2005 Tensilica Inc.
10  * Copyright (C) 2015 Cadence Design Systems Inc.
11  *
12  * Based on version for i386.
13  *
14  * Chris Zankel <chris@zankel.net>
15  * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
16  */
17
18 #include <linux/gfp.h>
19 #include <linux/highmem.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/string.h>
24 #include <linux/types.h>
25 #include <asm/cacheflush.h>
26 #include <asm/io.h>
27
28 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
29                     enum dma_data_direction dir)
30 {
31         switch (dir) {
32         case DMA_BIDIRECTIONAL:
33                 __flush_invalidate_dcache_range((unsigned long)vaddr, size);
34                 break;
35
36         case DMA_FROM_DEVICE:
37                 __invalidate_dcache_range((unsigned long)vaddr, size);
38                 break;
39
40         case DMA_TO_DEVICE:
41                 __flush_dcache_range((unsigned long)vaddr, size);
42                 break;
43
44         case DMA_NONE:
45                 BUG();
46                 break;
47         }
48 }
49 EXPORT_SYMBOL(dma_cache_sync);
50
51 static void do_cache_op(dma_addr_t dma_handle, size_t size,
52                         void (*fn)(unsigned long, unsigned long))
53 {
54         unsigned long off = dma_handle & (PAGE_SIZE - 1);
55         unsigned long pfn = PFN_DOWN(dma_handle);
56         struct page *page = pfn_to_page(pfn);
57
58         if (!PageHighMem(page))
59                 fn((unsigned long)bus_to_virt(dma_handle), size);
60         else
61                 while (size > 0) {
62                         size_t sz = min_t(size_t, size, PAGE_SIZE - off);
63                         void *vaddr = kmap_atomic(page);
64
65                         fn((unsigned long)vaddr + off, sz);
66                         kunmap_atomic(vaddr);
67                         off = 0;
68                         ++page;
69                         size -= sz;
70                 }
71 }
72
73 static void xtensa_sync_single_for_cpu(struct device *dev,
74                                        dma_addr_t dma_handle, size_t size,
75                                        enum dma_data_direction dir)
76 {
77         switch (dir) {
78         case DMA_BIDIRECTIONAL:
79         case DMA_FROM_DEVICE:
80                 do_cache_op(dma_handle, size, __invalidate_dcache_range);
81                 break;
82
83         case DMA_NONE:
84                 BUG();
85                 break;
86
87         default:
88                 break;
89         }
90 }
91
92 static void xtensa_sync_single_for_device(struct device *dev,
93                                           dma_addr_t dma_handle, size_t size,
94                                           enum dma_data_direction dir)
95 {
96         switch (dir) {
97         case DMA_BIDIRECTIONAL:
98         case DMA_TO_DEVICE:
99                 if (XCHAL_DCACHE_IS_WRITEBACK)
100                         do_cache_op(dma_handle, size, __flush_dcache_range);
101                 break;
102
103         case DMA_NONE:
104                 BUG();
105                 break;
106
107         default:
108                 break;
109         }
110 }
111
112 static void xtensa_sync_sg_for_cpu(struct device *dev,
113                                    struct scatterlist *sg, int nents,
114                                    enum dma_data_direction dir)
115 {
116         struct scatterlist *s;
117         int i;
118
119         for_each_sg(sg, s, nents, i) {
120                 xtensa_sync_single_for_cpu(dev, sg_dma_address(s),
121                                            sg_dma_len(s), dir);
122         }
123 }
124
125 static void xtensa_sync_sg_for_device(struct device *dev,
126                                       struct scatterlist *sg, int nents,
127                                       enum dma_data_direction dir)
128 {
129         struct scatterlist *s;
130         int i;
131
132         for_each_sg(sg, s, nents, i) {
133                 xtensa_sync_single_for_device(dev, sg_dma_address(s),
134                                               sg_dma_len(s), dir);
135         }
136 }
137
138 /*
139  * Note: We assume that the full memory space is always mapped to 'kseg'
140  *       Otherwise we have to use page attributes (not implemented).
141  */
142
143 static void *xtensa_dma_alloc(struct device *dev, size_t size,
144                               dma_addr_t *handle, gfp_t flag,
145                               struct dma_attrs *attrs)
146 {
147         unsigned long ret;
148         unsigned long uncached = 0;
149
150         /* ignore region speicifiers */
151
152         flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
153
154         if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
155                 flag |= GFP_DMA;
156         ret = (unsigned long)__get_free_pages(flag, get_order(size));
157
158         if (ret == 0)
159                 return NULL;
160
161         /* We currently don't support coherent memory outside KSEG */
162
163         BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
164                ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
165
166         uncached = ret + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
167         *handle = virt_to_bus((void *)ret);
168         __invalidate_dcache_range(ret, size);
169
170         return (void *)uncached;
171 }
172
173 static void xtensa_dma_free(struct device *hwdev, size_t size, void *vaddr,
174                             dma_addr_t dma_handle, struct dma_attrs *attrs)
175 {
176         unsigned long addr = (unsigned long)vaddr +
177                 XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
178
179         BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||
180                addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
181
182         free_pages(addr, get_order(size));
183 }
184
185 static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
186                                   unsigned long offset, size_t size,
187                                   enum dma_data_direction dir,
188                                   struct dma_attrs *attrs)
189 {
190         dma_addr_t dma_handle = page_to_phys(page) + offset;
191
192         xtensa_sync_single_for_device(dev, dma_handle, size, dir);
193         return dma_handle;
194 }
195
196 static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
197                               size_t size, enum dma_data_direction dir,
198                               struct dma_attrs *attrs)
199 {
200         xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
201 }
202
203 static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,
204                          int nents, enum dma_data_direction dir,
205                          struct dma_attrs *attrs)
206 {
207         struct scatterlist *s;
208         int i;
209
210         for_each_sg(sg, s, nents, i) {
211                 s->dma_address = xtensa_map_page(dev, sg_page(s), s->offset,
212                                                  s->length, dir, attrs);
213         }
214         return nents;
215 }
216
217 static void xtensa_unmap_sg(struct device *dev,
218                             struct scatterlist *sg, int nents,
219                             enum dma_data_direction dir,
220                             struct dma_attrs *attrs)
221 {
222         struct scatterlist *s;
223         int i;
224
225         for_each_sg(sg, s, nents, i) {
226                 xtensa_unmap_page(dev, sg_dma_address(s),
227                                   sg_dma_len(s), dir, attrs);
228         }
229 }
230
231 int xtensa_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
232 {
233         return 0;
234 }
235
236 struct dma_map_ops xtensa_dma_map_ops = {
237         .alloc = xtensa_dma_alloc,
238         .free = xtensa_dma_free,
239         .map_page = xtensa_map_page,
240         .unmap_page = xtensa_unmap_page,
241         .map_sg = xtensa_map_sg,
242         .unmap_sg = xtensa_unmap_sg,
243         .sync_single_for_cpu = xtensa_sync_single_for_cpu,
244         .sync_single_for_device = xtensa_sync_single_for_device,
245         .sync_sg_for_cpu = xtensa_sync_sg_for_cpu,
246         .sync_sg_for_device = xtensa_sync_sg_for_device,
247         .mapping_error = xtensa_dma_mapping_error,
248 };
249 EXPORT_SYMBOL(xtensa_dma_map_ops);
250
251 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
252
253 static int __init xtensa_dma_init(void)
254 {
255         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
256         return 0;
257 }
258 fs_initcall(xtensa_dma_init);